@mijostyn I've cranked up F703 speakers in a large room with a powerful solid state amp, so loud I had to wear ear protection because I wanted to see when they would go into distortion. I do that because, you will only really, totally break in a speaker if you drive it just short of distortion for a while. Best way to do that is put the speakers in a back room, face them at each other and reverse the speaker cables on one.
Anyway, no, you won't need a subwoofer to get bass with authority below 50hz.
I'm not hearing anything that the posters above who have not heard the speaker but think the speaker must sound like, with my F703 speakers
These speculative posts without actually owning or listening to the product being discussed is a huge disservice this forum.